Extension Snagging Checklist: How to Inspect Your Builder's Work

The final payment to your builder is the most valuable thing you have. Once it's gone, your ability to get defects fixed goes with it. Builders who call back promptly when there's money outstanding have a habit of becoming hard to reach the week after final payment clears.

Snagging is how you protect that position. It's the systematic inspection of your completed extension before you sign off financially: a room-by-room, trade-by-trade assessment of every surface, fitting, socket, and structural element. Done properly, it tells you exactly what needs fixing, gives you a documented basis for withholding payment, and gives your builder a clear list of what they owe you.

Done badly (or done after you've paid), it's just a list of things that annoy you with no mechanism to get them fixed.